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At least 217 records · Page 12Linked to original sources
PubMed1992

Time perception: effects of sex and sound intensity on scales of subjective duration.

Six women and six men reproduced ten time intervals varying in logarithmic steps between 1.3 and 20 s. The durations were indicated by white noise of 10, 25, 40 and 55 dB SL, different sound intensities in different sessions. It was found that (i) greater sound intensity entails shorter reproductions, and (ii) reproductions by male observers are shorter than those by female, although for both (i) and (ii) there is an interaction with the standard durations. The data were treated in accordance with the "parallel-clock model" (Eisler, 1975), whereby the parameters of the psychophysical power function are determined from duration reproduction data. As in previous experiments (Eisler, 1975), the data showed a break in the function entailing two segments. The effect of sound intensity could be attributed to the exponent, which was lower for stronger noise, and the effect of sex to the weight coefficient of the upper relative to the lower segment of the psychophysical function, the coefficient being lower for men.

Adult↗
PubMed1994

The internal clock: electroencephalographic evidence for oscillatory processes underlying time perception.

It has been proposed that temporal perception and performance depend on a biological source of temporal information. A model for a temporal oscillator put forward by Treisman, Faulkner, Naish, and Brogan (1990) predicted that if intense sensory pulses (such as auditory clicks) were presented to subjects at suitable rates they would perturb the frequency at which the resulting pattern of interference between sensory pulse rates and time judgments would depend on the frequency of the temporal oscillator and so might allow the frequency to be estimated. Such interference patterns were found using auditory clicks and visual flicker (Treisman & Brogan, 1992; Treisman et al., 1990). The present study examines time estimation together with the simultaneously recorded electroencephalogram to examine whether evidence of such an interference pattern can be found in the EEG. Alternative models for the organization of a temporal system consisting of an oscillator or multiple oscillators are considered and predictions derived from them relating to the EEG. An experiment was run in which time intervals were presented for estimation, auditory clicks being given during those intervals, and the EEG was recorded concurrently. Analyses of the EEG revealed interactions between auditory click rates and certain EEG components which parallel the interference patterns previously found. The overall pattern of EEG results is interpreted as favouring a model for the organization of the temporal system in which sets of click-sensitive oscillators spaced at intervals of about 12.8 Hz contribute to the EEG spectrum. These are taken to represent a series of harmonically spaced distributions of oscillators involved in time-keeping.

Acoustic Stimulation↗
PubMed2004

Time perception depends on accurate clock mechanisms as well as unimpaired attention and memory processes.

We report a series of studies aimed at characterizing the relationships between duration judgments and slowing down of the internal clock, attention and memory deficits. Different groups of participants (elderly people, patients with Parkinson's disease, patients with severe traumatic brain injury, and patients with temporal lobe lesions) performed a duration reproduction task and a duration production task in two conditions: a control counting condition and a concurrent reading condition. Participants were also administered reaction time tasks, tapping tasks, and a battery of attention and memory tests. The results allow us to characterize the relationships between cognitive deficits and impaired duration reproductions and productions in each group. Moreover, results as a whole clarify the respective weight of processing speed, attention and memory in both tasks, and allow better insight into the theoretical models of psychological time.

Adolescent↗
PubMed2005

Time perception: components of the brain's clock.

We know the human brain contains some kind of clock, but determining its neural underpinnings and teasing apart its components have proven difficult. New work on the parietal cortex illustrates how single unit recording may be able to help.

Biological Clocks↗
PubMed2000

ERPs and PET analysis of time perception: spatial and temporal brain mapping during visual discrimination tasks.

ERPs were recorded from 12 subjects performing duration and intensity visual discrimination tasks which have been previously used in a PET study. PET data showed that the same network was activated in both tasks [P. Maquet et al., NeuroImage 3:119-126, 1996]. Different ERP waveforms were observed for the late latency components depending on the dimension of the stimulus to be processed: frontal negativity (CNV) for the duration task and parieto-occipital positivity (P300) for the intensity task. Using BESA software, the sources were first modelled with a "PET dipolar model" (right prefrontal, right parietal, anterior cingulate, left and right fusiforms). To obtain a better fit for ERPs recorded in each task, two sources (cuneus, left prefrontal area) had to be added. Consistently with PET findings, dipole modelling indicates that duration and intensity dimensions of a visual stimulus are processed in the same areas. However, ERPs also reveal prominent differences between the time course of the dipole activations for each task, particularly for sources contributing to the late latency ERP components. In the intensity task, dipoles located in the cuneus, the anterior cingulate, and the left prefrontal area yield largest activity within the P300 interval, then activity diminishes rapidly as the stimulus ends, whereas in the duration task, the cuneus and anterior cingulate are still active several hundred milliseconds following stimulus offset. Moreover, in the duration task, the activity of the right frontal dipole parallels the CNV waveform, whereas in the intensity task, this dipole is largely inactive. We assume that the right frontal area plays a specific role in the formation of temporal judgments.

Adult↗
PubMed1978

Ethnic differences in time perception: a comparison of Anglo and Mexican Americans.

Social scientists have presented an image of the Mexican American as locked into the present, incapable, or unwilling to project plans and events into the future. This is seen as responsible in part for the lack of social mobility and assimilation exhibited by Mexican Americans. However, there is little empirical support for the contention that Mexican Americans have a restricted sense of future events. The present study compared the temporal perspectives of 31 Mexican American and 41 Anglo American college students. No marked differences were observed.

Adult↗
PubMed1977

Time perception and hemodialysis.

Subtle alterations in neurological function are often difficult to identify and even harder to quantitate. The identification of a neurotoxic state existing before overt behavioral changes occur has eluded quantification. It was hypothesized that a challenging signal-detection procedure would be used to assess neurological function of dialysis patients and other subjects, the degree of uremic toxicity occuring during an interdialytic interval, and the effects of neuroactive drugs. A vigilance task demanding the detection of an irregularly flashing light from a matrix of regularly flashing lights was administered to 3 groups of 15 men: patients undergoing maintenance hemodialysis, patients with chronic illness and no kidney disease, and healthy subjects. The procedure was found to yield a reliable measure; average test-retest correlation was 0.93, which differentiated not only within the hemodialysis cycle (p less than 0.001), between groups (p less than 0.001), but was also related to the recency of neuroactive drugs ingested (p less than 0.01).

Arthritis↗
PubMed1996

Time perception as a complex functional system: neuropsychological approach.

Ninety-two brain-damaged patients and 111 normal control subjects were tested on their orientation to date; sequencing of events; discrimination of simultaneity and succession; conditioning to time; comparison, production and reproduction of durations; conservation of velocity in clocks; construction of time units; and psychological time. Temporal disorientation was related to advanced age, low educational level, amnesia, dementia and limbic or diffuse brain lesions. Only multifocal-diffuse lesions accompanied by dementia could disintegrate the concept of metric time, while sparing psychological time, discrimination of durations and sequencing of canonically recurring events. Reproduction of durations and verbally mediated temporal conditioning were impaired in frontal and temporal-limbic lesions, which left intact the concept of time. The results support the hypothesis that temporal perception is accomplished by a complex functional system, regarding both its psychological structure and cerebral organization.

Adolescent↗
PubMed1999

An experiment in time perception: separating rate of presentation from type of estimation.

An experiment was conducted to distinguish between studies which show main effects versus interaction effects regarding estimations of time as a function of the rate (fast or slow) of digit presentation and the type (immediate or delayed) of time estimation. Undergraduate volunteers (36 men and 103 women) gave retrospective estimates of time following a short-term memory filler task consisting of memorizing a series of random digits (1-5) which varied in length (25 or 50 digits). Rate was manipulated by altering the interstimulus interval between digits (100 msec. or 1,300 msec.) or by varying the length of the list. A multivariate analysis of variance showed significant main effects for type of time estimation (delayed estimates were longer than immediate), length of list (estimates for 50 digits were longer than for 25), and interstimulus interval (estimates for 1,300 msec. were longer than for 100 msec.) yet, contrary to Pedri and Hesketh in 1993, there were no significant interactions among the variables. Each of the independent variables was associated with effects on time estimation and short-term memory which were the same at all levels of the other variables. Task variables were discussed as a potential source of variance among past studies.

Attention↗
PubMed2005

Electrophysiological correlates of temporal generalization: evidence for a two-process model of time perception.

In an event-related potential (ERP) study, brain correlates of temporal processing in the range of milliseconds were investigated by means of a dissociation paradigm. For this purpose, ten male and ten female subjects performed temporal and pitch generalization tasks with uni- and bidimensional stimulus variation. With difficulty held constant for both tasks, a larger frontally distributed negative slow wave was observed for pitch generalization relative to temporal generalization. This ERP pattern was consistent across uni- and bidimensional tasks of the present study but in direct contrast to prior ERP studies on temporal processing. Furthermore, for both uni- and bidimensional temporal tasks, within-task ERP analyses yielded amplitude modulation of centro-parietal P3b and fronto-central P500 as brain correlates of actively processed stimulus duration. Findings were consistent with a two-process model of temporal information processing based on a real-time comparison of the presented stimulus duration against an internal representation of the standard duration.

Adult↗
PubMed1986

Voice onset time perception in Japanese aphasic patients.

This study examines identification of the synthetic speech stimuli [ga] and [ka] of varying voice onset times (VOTs) in 17 Japanese aphasic subjects. Approximately two-thirds of the aphasic subjects showed deterioration in performance of VOT identification of the stimuli. A quantitative analysis of the results indicates that the problems of the majority of these subjects may be attributable not only to difficulty in labeling the stimuli but also to difficulty in processing the acoustic and/or phonetic information of the stimuli.

Adult↗